Work tool assembly and coupler

ABSTRACT

A coupler for detachably coupling to a work tool includes a first coupling member connected with an arm of an equipment. The first coupling member includes a first pair of actuators. A second coupling member connected with a link of the arm includes a second pair of actuators. A plate member is adapted to couple with each of the first coupling member and the second coupling member. The plate member includes a connecting member to engage with the work tool.

TECHNICAL FIELD

The present disclosure relates generally to a work tool assembly. More particularly, the present disclosure relates to a coupler of the work tool assembly.

BACKGROUND

Earth moving equipment, such as excavator, backhoes, or loaders typically includes a moveable arm that connects with a work tool. The work tool may be integrally connected with the arm or may be detachably connected with the arm. In the detachable connection, a coupler acts as an interface between the work tool and the arm. The coupler detachably connects the work tools, such as buckets, breaker, crusher, vibration hammer, etc. to the arm. Couplers may also allow a user to quickly change from one work tool to another. Such couplers may be referred to as quick couplers.

The couplers may require a cylinder force from the arm to couple and lock with the work tool. Moreover, the couplers may increase tip radius between the arm and the work tool, thereby reducing leverage applied to the work tool by the arm and thus, affect a performance of the work tool.

U.S. Pat. No. 6,513,268 relates to a device for coupling an implement to an operating arm of an excavator. The arm includes an additional link for guiding the coupling mechanism. The coupling member pivotally connects the arm and link of the excavator. The coupling device includes a piston member, which is resiliently biased by a spring, and facilitates the slidable communication between the coupling member and the work tool. A joining plate connects the sliding ends of the piston members located in the arm and the link. The joining plate includes a groove, wherein the groove is locked with a position guide during the coupling action. As the position guide is separately connected with the link and the arm, the surface contact of the coupler with the work tool may be less and the performance of the coupling mechanism may be affected. Hence, there is a need of an improved coupling mechanism.

SUMMARY OF THE DISCLOSURE

In an aspect of the present disclosure, a coupler for detachably coupling to a work tool is provided. The coupler includes a first coupling member, a second coupling member and a plate member. The first coupling member includes a first pair of actuators. The second coupling member connected with a link of the arm and includes a second pair of actuators. The plate member adapted to couple with each of the first coupling member and the second coupling member. The plate member includes a connecting member to engage with the work tool.

In another aspect a method of coupling a coupler with a work tool of a machine is provided. The coupler having a first coupling member, a second coupling member, a first side plate member, a second side plate member, and a connecting member provided on a surface of the first side plate member and the second side plate member. The method includes retracting a machine actuator to place the coupler in an upright position. The method further includes engaging the first coupling member by a pair of hooks provided on a connecting portion of the work tool, wherein the first coupling member includes a first pair of actuators in a first position. The method further includes extending the machine actuator to place the second coupling member of the coupler on a pair of detents provided on the connecting portion of the work tool, wherein the second coupling member includes a second pair of actuators in the first position. The method further includes moving the first pair and the second pair of actuators from the first position to a second position such that first side plate member and the second side plate member moves laterally towards each other and the connecting member provided on the first side plate member and the second side plate member engage with the work tool to lock the coupler with the work tool.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an isometric view of an implement assembly including a coupler and a work tool, in accordance with an embodiment of the present disclosure;

FIG. 2 is a partially exploded view of the implement assembly of FIG. 1, in accordance with an embodiment of the present disclosure;

FIG. 3 is a sectional view of a first coupling member connected with an arm of a machine of FIG. 1, in accordance with an embodiment of the present disclosure;

FIG. 4 is a perspective view of another embodiment of the coupler of the present disclosure;

FIG. 5 is a perspective view of the coupling mechanism with the coupler is positioned in an unlocked position with respect to the work tool, in accordance with an embodiment of the present disclosure;

FIG. 6 is a perspective view of the coupling mechanism with a first coupling member engaged with the work tool, in accordance with an embodiment of the present disclosure;

FIG. 7 is a perspective view of the coupling mechanism with a second coupling member engaged with the work tool, in accordance with an embodiment of the present disclosure; and

FIG. 8 is a perspective view of the coupling mechanism with the coupler is positioned in a locked position with respect to the work tool, in accordance with an embodiment of the present disclosure.

DETAILED DESCRIPTION

Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or the like parts. Referring to FIG. 1, an implement assembly 100 is illustrated. The implement assembly 100 includes an arm 102, a first link 104, a second link 106, a coupler 108 and a work tool 110. The arm 102 may be a work arm of a machine (not shown), for example, an excavator, backhoe, loader, or the like. The arm 102 may provide motive force to the work tool 110 via the coupler 108.

The first link 104 is pivotally connected to the arm 102 via a first pin joint 112. Further, a second pin joint 114 pivotally connects the first link 104 to the second link 106. A first coupling member 116 pivotally connects the arm 102 to the coupler 108, while a second coupling member 118 pivotally connects the second link 106 to the coupler 108. In an embodiment, the first coupling member 116 and the second coupling member 118 are components of the coupler 108. A machine actuator 119, such as a hydraulic cylinder, may be provided between the arm 102 and the second link 106 to provide additional actuation of the work tool 110 via the coupler 108, such as rotation of the coupler 108 and the work tool 110 relative to the arm 102 about the second coupling member 118. In the illustrated embodiment, the work tool 110 is an excavating bucket having multiple excavating teeth 120 at a lower end 122. However, in alternative embodiments, the work tool 110 may be a ripper, a drill, and the like.

Referring to FIG. 2, the arm 102 includes an arcuate portion 123. The arcuate portion 123 pivotally forms a rolling pair contact with the first coupling member 116. Similarly, the second link 106 includes an arcuate portion 125 to form a rolling pair contact with the second coupling member 118. In various embodiments, the first and the second coupling members 116, 118 may be coupled with the arm 102 and the second link 106 respectively by any suitable joining methods such as, but not limited to, welding, through rivets, forging and the like.

In an embodiment, the second link 106 includes a lifting eye 127 located in a central-mid surface of the second link 106. However, the lifting eye 127 may be positioned anywhere on the second link 106, such as a central-top surface, a central-bottom surface, and the like. The lifting eye 127 may also be used to lift material while the coupler 108 is connected or disconnected from the work tool 110.

In an embodiment, the first and the second coupling members 116, 118 includes a first pair of actuators and a second pair of actuators respectively. As illustrated in the FIG. 3, the first pair of actuators includes a first piston 128 and a second piston 130. The first and second pistons 128, 130 are partially enclosed in a first cylinder barrel 124. The first and second pistons 128, 130 are resiliently biased in the first cylinder barrel 124. The first and second pistons 128, 130 are configured to move laterally with respect to the first cylinder barrel 124. As illustrated in FIG. 3, the first piston 128 is resiliently biased by a first spring 132 and the second piston 130 is resiliently biased by a second spring 134. In an embodiment, the first and the second springs 132, 134 are disc springs. However, the springs 132, 134 may be any other resilient element, for example, an air spring, a coil spring, and a volute spring.

The second coupling member 118 (as shown in FIG. 2) may have a similar construction to the first coupling member 116. As such, the second pair of actuators of the second coupling member includes a first piston 136 and a second piston 138. The first and second pistons 136, 138 are partially enclosed in a second cylinder barrel 126. The first and second pistons 136, 138 are configured to move laterally with respect to the second cylinder barrel 126. The first and the second pistons 136, 138 are resiliently biased in the second cylinder barrel 126.

In an embodiment, the first pair of actuators and the second pair of actuators as pistons 128, 130, 136 and 138 may be extended by an application of hydraulic force and retracted by the action of resilient force. In various other embodiments of the present disclosure, the first pair of actuators and the second pair of actuators may include manual or electric screw actuator. In case of electric screw actuator, the actuators may be extended and retracted by an electric power provided either through an engine of the machine or through any alternate power source, such as, battery provided on the machine.

With combined reference to FIGS. 2 and 3, the coupler 108 includes a first side plate member 140 and a second side plate member 142. The first side plate member 140 is coupled to the first piston 128 of the first coupling member 116 and the first piston 136 of the second coupling member 118. Specifically, the first side plate member 140 has a pair of bosses 144 fixedly attached on to a surface 146 of the first side plate member 140. The bosses 144 may be attached to the surface 146 by any method known in the art, including, but not limited to, welding, forging and the like. Each of the pair of bosses 144 includes an aperture which is axially aligned with an aperture defined on a distal end of the first piston 128 of the first coupling member 116 and the first piston 136 of the second coupling member 118, to receive a mechanical fastener 148 therethrough and couple the first side plate member 140 with the first coupling member 116 and the second coupling member 118.

Similarly, the second side plate member 142 is fixedly attached to the second piston 130 of the first coupling member 116 and the second piston 138 of the second coupling member 118.

As described above, the first side plate member 140 and the second side plate member 142 connects the first and second pistons 128, 130 of the first coupling member 116 with the first and second pistons 136, 138 of the second coupling member 118. Thus, any movement of the first and second pistons 128, 130 of the first coupling member 116 may actuate a movement of the first and second pistons 136, 138 of the second coupling member 118 and vice versa. In an embodiment, the first and second pistons 128, 130 of the first coupling member 116 may be actuated to move to an extended position by application of hydraulic force and the first and second pistons 136, 138 of the second coupling member 118 moves in tandem to the extended position based on a movement of the first and second pistons 128, 130 of the first coupling member 116. Similarly, on disconnecting the application of the hydraulic force from the first coupling member 116, the first and second pistons 128, 130 of the first coupling member 116 moves to a retracted position and the first and second pistons 136, 138 of the second coupling member 118 moves in tandem with the movement of the first and second pistons 128, 130 of the first coupling member 116. In another embodiment, the first and second pistons 136, 138 of the second coupling member 118 may be actuated to move to an extended position by application of hydraulic force and the first and second pistons 128, 130 of the first coupling member 116 moves in tandem to the extended position based on a movement of the first and second pistons 136, 138 of the second coupling member 118. Similarly, on disconnecting the application of the hydraulic force from the second coupling member 118, the first and second pistons 136, 138 of the second coupling member 118 moves to a retracted position and the first and second pistons 128, 130 of the first coupling member 116 moves in tandem with the movement of the first and second pistons 136, 138 of the second coupling member 118. In another embodiment, the first and second pistons 128, 130 of the first coupling member 116 and the first and second pistons 136, 138 of the second coupling member 118 are actuated to move to an extended position by application of hydraulic force in each of the first coupling member 116 and the second coupling member 118.

In another embodiment, the first coupling member 116 and the second coupling member 118 are dual acting piston cylinders. In such a case, the first piston 128 and the second piston 130 of the first coupling member 116 and the first piston 136 and the second piston 138 of the second coupling member 118 may not be resiliently biased by the first spring 132 and the second spring 134 (shown for first coupling member 116 in FIG. 3). With the dual acting functionality, the hydraulic force may be used for both the extraction and retraction of the pistons 128, 130, 136 and 138 which may lead to disengaging and engaging of the coupler 108 with the work tool 110.

Referring to FIG. 2, the first side plate member 140 includes a connecting member 150 defined on the surface 146. Similarly, the second side plate member 142 has a connecting member (not shown) defined on a surface of the second side plate member 142. In the illustrated embodiment, the connecting member 150 is shown as slot 150. The slot 150 is a rectangular opening. However, the slot 150 may be an opening of any shape, such as a circular shape, a square shape.

As shown in FIG. 2, the work tool 110 also includes a connecting portion 152 for coupling the work tool 110 with the coupler 108. The connecting portion 152 includes a first plate 154 and a second plate 156 separated laterally from the first plate 154. The first plate 154 and the second plate 156 together include a pair of hook members 157 and a pair of detents 158. In one embodiment, each of the first plate 154 and the second plate 156 includes a guide member 160 extending outwardly from the first plate 154 and the second plate 156 respectively. In the illustrated embodiment, the guide members 160 have a rectangular profile. However, the guide members 160 may have any profile, such as a circular profile, a square profile.

In other embodiments, the connecting member 150 may include the guide member on the first side plate member 140 extending outwardly and towards the second side plate member 142, and similarly the second side plate member 142 also includes the guide member extending outwardly and towards the first side plate member 140. In such a case, the first plate 154 and the second plate 156 of the work tool 110 may include corresponding slots for the guide members of the first side plate member 140 and the second side plate 142.

In various other embodiments, another coupler such as coupler 162, as illustrated in FIG. 4 is used for locking with the work tool 110. As shown in FIG. 4, the coupler 162 includes a first pin 164 as the first coupling member and a second pin 166 as the second coupling member. Further, the coupler 162 includes a first side plate member 168 and a second side plate member 170 similar to that of the coupler 108, and the first and second side plate members 168, 170 movably connects with the first pin 164 and the second pin 166. The coupler 162 also includes a resilient member 172 at each connection end of the first and second pins 164, 166 and the first and second side plate members 168, 170. The first pin 164 and the second pin 166 also includes a spacer member 174 for receiving the pair of hooks 157, and the pair of detents 158 respectively.

Further, the coupler 162 also includes a hydraulic actuator 176 connected in between the first and second side plate members 168, 170. The hydraulic actuator 176 provides the necessary hydraulic force to overcome the resistance provided by the resilient member 172 and moves the first and second side plate members 168, 170 to an extended position. The first and second side plate members 168, 170 also includes a slot 178 proximal to the connection point of the second pin 166 with the first and second side plate members 168, 170. The slot 178 engages a wedge member (similar to guide member 160 of coupler 108) provided on the work tool 110 to lock the work tool 110 with the coupler 162 while the first and second side plate members 168, 170 are in a retracted position.

INDUSTRIAL APPLICABILITY

The present disclosure is applicable to machines, such as excavators, that are used for multiple functions. For example, an excavator may be used for excavating dirt, rock and other material, and during the excavation operations different implements may be required, such as a different size of bucket, an impact breaker or a grapple. The implement assembly 100 can be used to quickly change from one implement to another with ease, thus reducing a time period for which the machine may be unavailable for its intended purpose.

An exemplary connection process of the work tool 110 with the coupler 108 will now be described with reference to FIGS. 5 to 8. FIG. 5 shows the machine actuator 119 in a retracted position so that the coupler 108 is in an upright position. Also, the first piston 128 and the second piston 130 of the first coupling member 116 are in a first position, i.e. an extended position. Similarly, the first piston 136 and the second piston 138 of the second coupling member 118 are in an extended position. In an embodiment, a hydraulic actuator (not shown) may supply the hydraulic force in terms of hydraulic fluid for actuating the pistons 128, 130, 136 & 138 to the extended position. In an alternative embodiment, the hydraulic force is provided to either the first and the second pistons 128, 130 of the first coupling member 116 or the first and second pistons 136, 138 of the second coupling member 118. As the first coupling member 116 and the second coupling member 118 are attached through the first and second side plate members 140, 142, both the first and second pistons 128, 130 of the first coupling member 116 and the first and the second pistons 136, 138 of the second coupling member 118 move in tandem based on application of hydraulic force to any of the first coupling member 116 or the second coupling member 118.

Subsequently, as shown in FIG. 6, the pair of hook members 157 engages the first coupling member 116. Specifically, the pair of hook members 157 engages the first piston 128 and the second piston 130 of the first coupling member 116. The pair of hook members 157 engages a portion of the first piston 128 between the first side plate member 140 and the first cylinder barrel 124 and similarly, a portion of second piston 130 between the second side plate member 142 and the first cylinder barrel 124.

Subsequently, as shown in FIG. 7, the machine actuator 119 is in an extended position. The machine actuator 119 pushes the second coupling member 118 to rest on the pair of detents 158. Specifically, a portion of the first piston 136 between the first side plate member 140 and the second cylinder barrel 126 and a portion of the second piston 138 between the second side plate member 142 and the second cylinder barrel 126 rest on the pair of detents 158. Further, the slot 150 on the first side plate member 140 and the slot 150 on the second side plate member 142 axially align with the guide members 160 provided on the first plate 154 and the second plate 156 of the connecting portion 152 of the work tool 110.

Subsequently, as shown in FIG. 8, the work tool 110 is coupled with the arm 102 through the coupler 108. The hydraulic actuator (not shown) withdraws the hydraulic power from the first and second coupling members 116, 118. In absence of the hydraulic force, the pistons 128, 130, 136 & 138 moves to a second position i.e. a retracted position by the action of springs 132, 134 (only shown for first coupling member 116) in the first and second coupling members 116, 118. The retraction of pistons 128, 130, 136 & 138 in the first and second coupling members 116, 118 of the coupler 108 laterally moves the first and second side plate members 140, 142 towards each other. As discussed above, the hydraulic force may be provided to either the first and the second pistons 128, 130 of the first coupling member 116 or the first and second pistons 136, 138 of the second coupling member 118. Thus, after disconnecting the hydraulic force, both the first and second pistons 128, 130 of the first coupling member 116 and the first and the second pistons 136, 138 of the second coupling member 118 move in tandem.

Accordingly, the connecting member 150 which is shown as slot 150 in FIG. 7, in the first and second side plate members 140, 142 engage the guide members 160 in the first and second plate 154, 156 respectively. The lateral movement of the first and second side plate members 140, 142 locks the coupler 108 with the work tool 110. As the coupler 108 locks the work tool 110 while being in a retracted position, no hydraulic force is required for locking the work tool 110 with the coupler 108. Therefore, the present disclosure provides safeguard against events such as a case of hydraulic failure. In other embodiments, the connecting member 150 on the first and second side plate members 140, 142 may include guide member (not shown) and there may be corresponding slots in the first and second plate 154, 156 of the work tool. In such cases, the guide member on the first and second side plate members 140, 142 engages with the slots on first and second plate 154, 156 to lock the coupler 108 with the work tool 110.

In various other embodiments, the implement assembly 100 may also include additional locking means (not shown) to provide a robust engagement of the coupler 108 with the work tool 110.

Further, the coupler 108 is locked with the work tool 110 for performing lifting operation in zero offset condition. Also, the engagement of the present coupler 108 with the work tool 110 provides more surface contact and thus, provides a robust engagement between the coupler 108 and the work tool 110.

In an embodiment, instead of the coupler 108, the lifting eye 127 of the second link 106 may be used for performing the lifting operation. A lifting rope (not shown) may be coupled with the lifting eye 127 for performing the lifting operation. As compared to the couplers provided in prior art, the geometry of the coupler 108 allows using the lifting eye 127 on the second link 106 to lift loads.

For the purpose of disconnecting the coupler 108 from the work tool 110, the hydraulic actuator may supply hydraulic fluid to outwardly extend the pistons 128, 130, 136 & 138 in the first and second coupling members 116, 118 respectively. Consequently, the slots 150 and the guide members 160 slide out of engagement as the first and second side plate members 140, 142 move laterally outwardly relative to each other. Thus, the coupler 108 provides for easy connection and disconnection of the work tool. The ease in connection and disconnection provides for a reduction in downtime of the machine.

In another embodiment, the first coupling member 116 and the second coupling member 118 are dual acting piston cylinders and the pistons 128, 130, 136 and 138 may not be resiliently biased by the first spring 132 and the second spring 134 (shown for first coupling member in FIG. 3). In such a case, the hydraulic force may be provided for having the first piston 128 and the second piston 130 of the first coupling member 116 and the first piston 136 and the second piston 138 of the second coupling member 118 in the first position. Similarly, the hydraulic force may be provided for moving the first piston 128 and the second piston 130 of the first coupling member 116 and the first piston 136 and the second piston 138 of the second coupling member 118 from the first position to the second position. Thus, the locking and unlocking of the coupler 108 with the work tool 110 is achieved based on the dual acting functionality of the first coupling member 116 and the second coupling member 118.

In various other embodiments of the present disclosure, instead of the pistons 128, 130, 136 and 138, the first coupling member 116 and the second coupling member 118 includes a first pair of electric screw actuators and a second pair of electric screw actuators respectively. In such case, an electric power is provided for moving the first pair of actuators and the second pair of actuators from the first position to the second position for locking the coupler 108 with the work tool 110.

In various other embodiments, and as explained in FIG. 4, the coupler 162 includes the first pin 164 as the first coupling member and the second pin 166 as the second coupling member. The hydraulic actuator 176 of the coupler 162 provides the necessary hydraulic force to move the first side plate member 168 and the second side plate member 170 to a first position i.e. the extended position, where the first pin 164 contacts the pair of hooks 157 of the work tool 110 and the second pin 166 contacts the pair of detents 158 of the work tool 110. Specifically, the spacer members 174 of the first and second pin 164, 166 contact the pair of hooks 157 and the pair of detents 158 respectively.

Subsequently, the hydraulic actuator 176 withdraws the hydraulic force and as a result, the first side plate member 168 and a second side plate member 170 moves laterally towards each other due to the action of the resilient member 172 provided at each connection end of the first and second pins 164, 166 and the first and second side plate members 168, 170. As the first and second side plate members 168, 170 moves to a second position i.e. the retracted position, the slot 178 provided on each of the first and second side plate members 168, 170 engages with the wedge member (similar to guide member 160 of coupler 108) provided on the work tool 110 to lock the coupler 162 with the work tool 110.

While aspects of the present disclosure have been particularly shown and described with reference to the embodiments above, it will be understood by those skilled in the art that various additional embodiments may be contemplated by the modification of the disclosed systems and methods without departing from the spirit and scope of what is disclosed. Such embodiments should be understood to fall within the scope of the present disclosure as determined based upon the claims and any equivalents thereof. 

What is claimed is:
 1. A coupler for detachably coupling to a work tool, the coupler comprising: a first coupling member connected with an arm of an equipment, the first coupling member includes a first pair of actuators, a second coupling member connected with a link of the arm, the second coupling member includes a second pair of actuator; and a plate member adapted to couple with each of the first coupling member and the second coupling member, the plate member includes a connecting member to engage with the work tool.
 2. The coupler of claim 1, wherein the first pair of actuators and the second pair of actuators include a manual or electric screw actuator.
 3. The coupler of claim 1, wherein the first pair of actuators includes a first pair of laterally moveable pistons partially enclosed in a first cylinder barrel and the second pair of actuators includes a second pair of laterally moveable pistons partially enclosed in a second cylinder barrel.
 4. The coupler of claim 3, wherein the first pair of laterally moveable pistons are extended based on an application of hydraulic force.
 5. The coupler of claim 3, wherein the second pair of laterally moveable pistons are extended based on an application of hydraulic force.
 6. The coupler of claim 3, wherein the first pair of laterally moveable pistons are extended and retracted based on a movement of the second pair of laterally moveable pistons.
 7. The coupler of claim 3, wherein the second pair of laterally moveable pistons are extended and retracted based on a movement of the first pair of laterally moveable pistons.
 8. The coupler of claim 3, wherein the first pair of laterally moveable pistons are resiliently biased in the first cylinder barrel and the second pair of laterally moveable pistons are resiliently biased in the second cylinder barrel.
 9. The coupler of claim 1, wherein the first coupling member is adapted to be received in a pair of hooks of a connecting portion of the work tool and the second coupling member is adapted to be received in a pair of detents of the connecting portion of the work tool.
 10. The coupler of claim 1, wherein the connecting member includes a slot provided on the plate member and the slot is engaged with a guide member of the work tool during a retracted position of the first pair of actuators and the second pair of actuators.
 11. The coupler of claim 1, wherein the connecting member includes a guide member provided on the plate member and the guide member is engaged with a slot on the work tool during a retracted position of the first pair of actuators and the second pair of actuators.
 12. The coupler of claim 1, wherein the plate member includes a pair of bosses to allow an engagement of the plate member with each of the first coupling member and the second coupling member.
 13. A method of coupling a coupler with a work tool of a machine, the coupler having a first coupling member, a second coupling member, a first side plate member, a second side plate member, and a connecting member provided on a surface of the first side plate member and the second side plate member, the method comprising; retracting a machine actuator to place the coupler in an upright position; engaging the first coupling member by a pair of hooks provided on a connecting portion of the work tool, wherein the first coupling member includes a first pair of actuators in a first position; extending the machine actuator to place the second coupling member of the coupler on a pair of detents provided on the connecting portion of the work tool, wherein the second coupling member includes a second pair of actuators in the first position; and moving the first pair of actuators and the second pair of actuators from the first position to a second position such that first side plate member and the second side plate member moves laterally towards each other and the connecting member on the first side plate member and the second side plate member engage with the work tool to lock the coupler with the work tool.
 14. The method of claim 13, wherein the first position is an extended position of the first and second pair of actuators and the second position is a retracted position of the first and second pair of actuators.
 15. The method of claim 13, wherein the first pair of actuators are laterally moveable pistons resiliently biased in a first cylinder barrel and the first pair of laterally moveable pistons is moved from the first position to the second position by disconnecting an application of hydraulic force in the first coupling member.
 16. The method of claim 13, wherein the second pair of actuators are laterally moveable pistons resiliently biased in a second cylinder barrel and the second pair of laterally moveable pistons is moved from the first position to the second position by disconnecting an application of hydraulic force in the second coupling member.
 17. The method of claim 13, wherein the first pair of actuators is moved from the first position to the second position based on a movement of the second pair of laterally moveable pistons from the first position to the second position.
 18. The method of claim 13, wherein the second pair of actuators is moved from the first position to the second position based on a movement of the first pair of laterally moveable pistons from the first position to the second position.
 19. The method of claim 13, wherein the connecting member includes a slot provided on the plate member and the slot engages a guide member of the work tool in the second position of the first pair of actuators and the second pair of actuators.
 20. The method of claim 13, wherein the connecting member includes a guide member provided on the plate member and the guide member engages a slot on the work tool during a second position of the first pair of actuators and the second pair of actuators. 